<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>css三角强化</title>
</head>
<style>
    .box {
        height: 25px;
        width: 150px;
        border: 1px solid red;
        margin: 200px auto;
        line-height: 25px;
        text-align: center;
    }

    .box .left {
        position: relative;
        float: left;
        height: 100%;
        width: 80px;
        background-color: red;
        font-size: 16px;
        font-weight: 700;
        color: white;
    }

    .box i {
        position: absolute;
        right: 0;
        top: 0;
        width: 0;
        height: 0;
        border-color: transparent white transparent transparent;
        border-style: solid;
        border-width: 25px 10px 0 0;
        /* border-width: 0 12px 13px 0; */
    }

    .right {
        font-size: 12px;
        color: gray;
        text-decoration: line-through;
    }
</style>

<body>
    <div class="box">
        <span class="left">
            ¥1650
            <i></i>
        </span>
        <span class="right">¥5650</span>
    </div>
</body>

</html>